Hi My name is Jim and I have a 1989 Invader 17 ft jet boat. Boat originally came with a much smaller motor. When I bought it I had no idea the motor was changed. The boat now has a Mercruiser 454 and I'm trying to find out more about the motor and could use some help. The only # I could get off the block is 10114182 and the firing order is 18436572. I'm trying to find out what year and hp it is. When I cross reference the serial # I get nothing. So I'm not sure if this is the right number or if I'm missing something? I did get this number off the back of the block near the flywheel and above the starter. Ty Jim.

J Google is your friend .......454 Mark V 91-95 4 bolt main........

That is the GM casting number and not a serial number. If it was a true Merc engine then it should be a 454mag which was rated at 365hp. There should be a Merc serial number tag near on the lower back starboard side of the engine.

engine serial dog tag above the starter.

I see the tag above the starter but can't make it out . Where else would the serial number be . I found that # just above the tag.

Also the only thing I could make out on the tag is Mercury.

That is the only place I know of. If it has an aluminum intake manifold and rect port heads, then it is a 454mag/365hp.

What years did they make that particular motor? I'm trying to figure out what year it is.

See post #2 GM manufactured the block from 91 to 95